Need to order copy of my deceased fathers birth certificate from PR

Need to order copy of my deceased fathers birth certificate from PR

My dad changed his name before he entered the army in 1941. I am trying to trace back his roots, but I need a copy of his birth certificate. He was born in Orocovis, Barros Puerto Rico..on Jan 15, 1919... He was either Almaberto or Humberto, then changed his name to Herbert. His last name was Morales by his father, Melendez by his mom. My aunt says my grandmas name was Josefa, but I found records here that show her name to be Marine? Because all of her children's names correspond to my dad's siblings, with Josefa's name similar siblings appear... This is crazy, My grandpa was a ladies man, so I'm stuck lol

I think if I could get the birth certificate it would help, but I've already tried with vitalcheck online and they were unable to assist. So I'm not sure where to go at this point.